Carl bohmeyeb



(No Model.)

0. BOHMEYER.

SECONDARY ELECTRIC CLOCK MOVEMENT. No. 386,103. PatentedJuly 17, 1888.

wrrsn STATES Parent Series.

B BOHMEYER, OF HALLEON-THE Si ALE, PRUSSTA, GERMANY.

SECGNDARY ELECTRlC-CLGGK MOVHVENT.

Si ECIFICATIDN forming part of Letters Patent No. 386,103, dated July 1'7, 1888.

Application filed February 20, 1888. Serial No. 261,690.

To aZZ whom it may concern:

3e i known that I, CARL BQHMEYER, a subjcct oi the Emperor of Germany, and a resident ot'Halle-onlhe Saale, Prussia, Germany, have invented a new and useful Improvement in Electric Clocks, (for which Ihave obtained patent in Germany, dated July 12, 1887, No. 42,183,)ofwhich thefollowingisaspecification.

This invention relates to clocks in which the hand or hands are moved by mechanism setin action by periodical electric currents; and the object of the invention is an improved meehanism in which the shafts of the hands are moved by levers operated by an armature so placed as to exercise great leverage while requiring but a feeble current for actuating it.

tel'erring to the accompanying drawings, Figure 1 is an elevaticnal view of the mech' anism as seen from the rear. Fig. 2 is a plan view of the clectro-n'iagnetic poles, showing the construction or shaping of the-ends of the cores.

A is a permanent magnet broadened at one end to form a plate, 0. On said plate are fastened by one end the cores a Z), carrying the coils B G. Said cores extend upward toward the opposite pole, (Z, of the permanent magnet A, and to this pole is pivoted a twoarmed armature, D. The cores ab,beingin connection with one end of the permanent magnet,become themselves magnetic, their upper poles being alike and contrary to the polarity of the armature cf, by reason of the connection of the latter with the opposite pole, d, of the permanent magnet.

The upper extremities of the cores a Z) project a convenient distance above their coils, and are cut away or recessed on one side, as g, for a convenient depth, as shown in Fig. 2, so that the respective wings cf of the armature I) may pass before the standing parts of the cores 0t 1), and thus the attraction of the re spcctive core upon the armature be exercised through a longer distance, this being necessary or advantageous by reason of the distance of the armature from the shaft of the hand, and thelonger travel therefore necessary to be given to the armature. 0n the shaft m of the armature D are two levers, k I, so placed that when the armature is in an intermediate position be- (No model.)

Patented in Germany July 12, 1887, No. 42,183.

fore the poles of the cores a b said levers may stand aligned with the line connecting the centers of the shafts a and g the one lever, 7.2, bc ing directed away from shaft the second lever, Z, directed toward said shaft. The shat't :0 may be weighted to normally stand in this position. In the drawings the lever Z carries a slight preponderance of weight for this purpose. This is not, however, essential to the mechanism. (311 the levers 7s and Z are pins engaging in the slots at the respective ends of the forked levers h '2", pivoted loosely on the shaft y of the minute-hand. On the said shaft is a ratchet-wheel, q, and on the said levers in are pawls a "m, respectively, engaging one behi nd the other in the teeth of the said ratchet. A train of wheels (not shown) of the usual nature drive the hour-hand, it there be one, from the minute-shaft y. Above the pawls n m are pins 0 1), whereby the engagement of the pawls with the teeth is assured. The coils B O are so wound that a current passing through them in the one or other direction forms of the cores a and b and baseplate c a horseshoe electro magnet, the coils a I) being of opposite polarit This clock is designed to be placed in electric connection with a central-station clock, in which an automatic pole-changer is arranged for changing the direction of the currentat definite intervals corresponding to the number of teeth on the ratchet-wheel q, so that the latter is caused to complete one revolution in each hour.

The operation of the mechanism is as follows: .Vhen a current passes through the coils B G, the armature is attracted to the pole of one core and repelled from the other. 1n the drawings the core a has attracted the arm c of the armature and the core I) repelled the arm j thereof. By this movement the upper lever, is, has moved the lever 72. and the latter revolved the ratchet-wheel bythe pawl a for a certain distance. The leverl has moved back the lever 2', so that the pawl m arrives behind the next tooth of the ratchet-wheel. \Vhen now a current passes in the opposite direction through the coils B O, the armature D is revolved, the pawl m propels the wheel q, and the pawl nis drawn back behind the next tooth.

IOO

The pins 01) are so vplaced as to prevent the ratchet-wheel from lifting the respective pawls not, by its momentum or otherwise, until withdrawal of the pawl from under the respective pins by backward movement of the lever.

I claim- 1. In an electric clock. the combination, with magnet A, of cores a I), in connection with one pole of said magnet, a two armed armature, D, in connection with the opposite pole of said magnet, coils B and C on said cores, levers kl h z, adapted to be operated by movement of said armature, as set forth, and pawls n m on said levers M, respectively, together with ratchet-wheel q, adapted to be revolved by said 15 pawls, for the purpose set forth.

2. The combination of magnet A, cores a I), having recesses g, coils B C thereon, armature D, having arms 6 f, levers is Z h 2', pawls n m, pins 0 p, and ratchet-wheel q, substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CARL BOHMEYER. Witnesses:

EDMUND Z0011, MAX MATH-xiii. 

